On Wed, 2021-09-29 at 18:33 +0200, Dafna Hirschfeld wrote: > > On 29.09.21 03:37, Yong Wu wrote: > > Prepare for adding device_link. > > > > The iommu consumer should use device_link to connect with the > > smi-larb(supplier). then the smi-larb should run before the iommu > > consumer. Here we delay the iommu driver until the smi driver is > > ready, > > then all the iommu consumers always are after the smi driver. > > > > When there is no this patch, if some consumer drivers run before > > smi-larb, the supplier link_status is DL_DEV_NO_DRIVER(0) in the > > device_link_add, then device_links_driver_bound will use WARN_ON > > to complain that the link_status of supplier is not right. > > > > device_is_bound may be more elegant here. but it is not allowed to > > EXPORT from https://lore.kernel.org/patchwork/patch/1334670/. > > > > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> > > Tested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx> # BPI- > > R2/MT7623 > > --- > > drivers/iommu/mtk_iommu.c | 2 +- > > drivers/iommu/mtk_iommu_v1.c | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index d837adfd1da5..d5848f78a677 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -844,7 +844,7 @@ static int mtk_iommu_probe(struct > > platform_device *pdev) > > id = i; > > > > plarbdev = of_find_device_by_node(larbnode); > > - if (!plarbdev) { > > + if (!plarbdev || !plarbdev->dev.driver) { > > of_node_put(larbnode); > > return -EPROBE_DEFER; > > if plarbdev is null doesn't that mean that the device does not exist? This is probe function, Is it possible the platform device is not ready at this time? I checked the platform device should be created at: of_platform_default_populate_init: arch_initcall_sync ->of_platform_populate ->of_platform_device_create_pdata Not sure if this may be delayed for some device. If not, it should be ENODEV here. > so we should return -ENODEV in that case? > > thanks, > Dafna > > > } > > diff --git a/drivers/iommu/mtk_iommu_v1.c > > b/drivers/iommu/mtk_iommu_v1.c > > index 1467ba1e4417..4d7809432239 100644 > > --- a/drivers/iommu/mtk_iommu_v1.c > > +++ b/drivers/iommu/mtk_iommu_v1.c > > @@ -602,7 +602,7 @@ static int mtk_iommu_probe(struct > > platform_device *pdev) > > } > > > > plarbdev = of_find_device_by_node(larbnode); > > - if (!plarbdev) { > > + if (!plarbdev || !plarbdev->dev.driver) { > > of_node_put(larbnode); > > return -EPROBE_DEFER; > > } > > > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-mediatek
